Melting-furnace.



T. W. MUCKLE.

MELTING FURNACE.

APPLICATION FILED MAR. 18, 1918.

1,286,719. Patented Dec. 3, 1918.

2 SHEETSSHEET l.

T. W. MUCKLE.

MELTING FURNACE.

APPLICATION FILED MAR. l8. I9I8.

1,286,719. Patented Dec. 3, 1918.

2 SHEETS-SHEET 2.

whim/ems umrnn smrrns PATENT orricn THEODORE W. MUCKLE, 01? DENVER, COLORADO, ASSIGNOR TO THE CASE MANUFAC- TUBING CORPORATION, 01? DENVER, COLORADO, A CORPORATION OF COLORADO.

MELTING-FURNACE.

Specification of Letters Patent.

Patented Dec. 3, 1918.

Application filed March 18, 1918. Serial No. 223,096.

To all whom it may concern:

Be it known that I, THEODORE W. MUcKL'E, a citizen of the United States, residing in the city and county of Denver and State of Colorado, have invented certain new and useful Improvements in Melting-Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will others skilled in the art to which it appertains to make, use, and carry out the same. i

This invention relates to improvements in melting furnaces for reducing the contents thereof to a molten state with exceeding rapidity and without oxidation occurring.

It is true that furnaces have heretofore been in use, employing inserted crucibles or like containers, wherein the heat applied to the metal to be melted is an indirect or a radiated heat, which will not, to any great extent, cause vaporization and oxidation of its volatile constituents, resulting in an oxidized scale-like scum or slag.

Manifestly, however, there are many objections to the use of crucibles, especially where the melting point of the metallic mass is 2000 F. or higher, or where the operations are to be carried out on a large scale; but for the present purpose of pointing out emphatically the great utility of my invention, it will suffice to simply mention the two primary drawbacks of the breakage of the large expensive crucibles and the length of time requisite to thoroughly melt their contents, each of which in itself is a costly waste in point of direct actual expense and great loss of time, both in melting the mass and in replacing cracked or broken crucibles.

In consequence means have been diligently sought for, whereby a naked blast flame and its hot gases might be utilized for positively directing an intense heat into intimate contact with the metallic mass, avoiding the use vof crucibles entirely; but heretofore such means have not been satisfactorily demonstrated or deemed wholly practicable, for the reason that when a blast flame strikes the metallic mass oxidation will occur, and in practice an oxidized scale or slaggy scum has been known to flow off of the molten mass, almost as a stream, where there is an escape therefor, which results in a total loss of a large quantity of the desired reduced metal for casting purposes, or for pouring pinge directly efore or after melting has been substan tially started or practically completed.

In carrying out my present invention, I take cognizance of this latter principle by the construction of a novel ty of furnace, whereby a highly intensifie naked blast flame, after conversion into its resultant hot gases, is caused to swirl therearound in such manner that the hot gases travel in a spiral sheet-like path from the rear to the forward pouring end thereof, withthe top and side walls of the furnace confining and directing the initial flame and its hot gases, after complete combustion has taken place, across the metallic mass itself, the said mass, whether partly or wholly molten, serving eventually as a bottom confining liquid wall or body surface for the blast, manifestly providing for a more direct and intimate heating of the molecular particles of said mass, but without causing the oxidation thereof. 1

Another feature is to produce an improved furnace, for carrying out the foregoing principle, which is not only simple in construction and operation, but is also durable, eiiicient in action, and inexpensive to manufacture and repalr.

comparatively As other objects and advantages will fully appear, as incidental to the following disclosure, it would only be unnecessary repetition to further state them initially, but to more clearly understand the details of the invention the improved furnace itself will Fig. 1, the supporting framework and exterior cooperating elements being shown in front elevation;

Before describing the furnace body proper, I will first refer to its supporting means and associated external arts, 7 as these are less material in detail an may be conveniently combined in any suitable way to provide a compactly arranged portable structure;

In the drawings this arrangement isshown a comprising a light skeleton iron framework 5, upon which the furnace body is tiltingly mounted by the solid trunnion 6'and hollow trunnion 7 which latter is in communication with a rotary blower 8,

preferably of the low pressure type, through the air conduit ipe 9, and is driven by any suitable form of motor, designated at 10 as an electric motor.

The outer end of the ihollow trunnion 7 is preferably of reduced diameter, to be 'journaled in the framework, and 1s mounted in rotatable connection with'the inturned or upper elbow end of the air conduit p1pe 9. This reduced end carries a worm gear wheel 11, meshing with a worm element (not appearing) on the shaft 12, operated by a I hand wheel 13, for turning the furnace body formation, with its delivery end flaring in-' wardly to spread out the blast flame upon ignition as it enters the melting chamber.

18 is a fuel oil or gas inlet pipe for the burner, and 19 indicates a damper arrangement for regulating the supply of air under pressure through the branch air pipe 14, while 20 designates the usual needle valve for controlling the admission of oil or gas,

as is well understood.

The melting chamber 21 is of a peculiar contour, for certain purposes as will hereinafter appear, and it is walled by a thickened refractory lining 22 of fire clay or its equivalent, set up as a replaceable whole or in sections as desired, and between which and an outer iron incasing sheathin 23there may be interposed a heat resistmg filling 24, such as asbestos or the like. The rear iron wall plate 25 may be flat and the front I wall incased in a conical iron shell 26, both -of which are detachably assembled to permit of the ready removal and replacing of the rethe fuel inlet 17 with 'fractory lining when required, the, whole outer casing being bound together around the furnace box by suitably arranged tie-rod connections. 7 a

The top wall of the furnace is apertured to provide a feed inlet opening 27 for the metal to be melted, while the front wall is also apertured to provide a pouring outlet, which also serves as an exit for exhausting the spent gases. he feed opening 27 is provided with any suitable form of closure, shown as a re cessed seating plug 29 of refractory mate rial, having lifting means or handles 30 and laterally projecting pins 31, the latter being adapted to interlockingly cooperate with oppositely leasing and locking the closure plug by a slight rotation of the same.

It will be noted that the inner face 33.

of the top wall of the melting chamber is of arched, or semi-cyllndrical, lateral curvature to approxlmately the position of the pouring outlet 28, but the inner face 34 of the bottom Wall terminates short of the radius of said arch and is -flat surfaced, while the front wall is conically shaped to provide a retarding reverberative surface 35. Also the inner flaring upper surface of the fuel inlet opening 17 is substantially in tangential line with the curved top surface 33 of the melting chamber. Most of these disposed hooked pins 32, for refeatures I deem to beof material importance,

in the functioning of my improved furnace as will presently appear, and I desire, therefore, to emphasize the point, before proceeding with an exact statement of operation itself, which now will have been fairly apparent and may be briefly set forth as follows.

At first a suitably proportionate charge of the metal to, be melted, scrap or otherwise, is introduced through the feed opening 27, and as it becomes partiallymelted, fter the furnace gets fairly started, additional charges are added, so that the molten or partially molten mass rises in the bottom-of the melting chamber until an approximate desired level is reached, indicated at the dotted line 37 just below the bottom of the pouring outlet 28 to prevent any splashing or slopping out therethrough from the im-,

pact of the blast, which is directed through powerful force, and is immediately ignited with a resultant highly intensive degree of heat.

This blast flame and its entrained hot same at this gases spread out in a sheet-like form as they are deflected around the curved surface 33 downwardly toward and across the liquid surface line, in the direction as indicated by the arrows a, which liquid surface comprises the bottom confining boundary thereof; but

before the flame and hot gases have reached the semi-molten mass complete combustion oxygen removed, the oxidation of any metallic values is also eliminated.-

- ing chamber being ling action,

As the blast of hot gases strikes this liquid surface the latter becomes agitated or rifiled to some considerable extent thereby,-

causing a constantly changing molecular surface, and hence a more intimate heating of the particles thereof, thus reatly accelerating the melting operation; ut even outside of this feature, the bottom of the melta fiat surface, instead of curved concavely, the depth of the molten mass will be uniformin any vertical plane transversely cutting the same. Consequently the heating of the bodily mass is proportionately uniform, which would not be'the case with a concave bottom surface. This will be equally true, whether the furnace body is in a direct horizontal position, as shown, or slightly tilted upwardly at its pouring end, although in the latter instance the depth of the mass will not'be uniform relatively to a vertical longitudinal plane cutting the same, as the depth at the rear will be slightly greater than toward the front, but for all practical purposes this will be compensated for and the heating of the bodily mass will be commensurately uniform, as the entering blast, at its highest degree of intensity, will first act on the thicker portion, in its spirally advancing path to the outlet end of the furnace, as indicated by the upwardly directed and forwardly curving arrows b, while the retarding reverberative surface 35 will aid in equalizing, to a substantial degree, the heat at the forward end of the furnace, as will further appear.

From the foregoing, therefore, it will be seen that the sheet-like blast ofvhot gases,

resulting from the naked blast flame after complete combustion has {taken place, is caused to traverse the length of the furnace, in a swirling spirally advancing path across the whole exposed surface of the melting mass and with a non-oxidizable direct heatcal deflecting wall 35, when partial rearward reverberation results before final expulsion of the then almost spent gases through the outlet 28, thus additionally maintaining the full intensity of the heat within the furnace at its forward end.

Melting may be continued as long as necessary, and after total melting, the operation of pouring will be a parent, without further description, the urnace being of the tilting type, rotatably mounted on its trunnions as heretofore described, for facilitating this pouring.

In actual operations I have made complete successive meltings, with little or no waste resulting from the formation of an oxidized slag-like scum, and in an incomparably short and until striking the forward conispace of time, relatively to methods heretofore employed.

Finally I do not limit myself to the exact steps and details of the invention as specifically disclosed, excepting as they fall within the purview of the ensuing claims, when construed in the light of the specification,

contemplating a fair range of equivalents,

but what I do claim, able, is 2- 1. A potless melting furnace,

as new and patentadaptcd to be disposed in substantial horizontal position, having a melting chamber with a flat surfaced bottom, and being provided with a fuel inlet toward the top rear end thereof and an outlet toward the opposite forward end. in combination with means for introducing a fuel mixture, directed through said inlet, in the form of a strong blast flame proj ected across the top of said chamber and down its opposite side wall, for permitting of its substantial complete combustion before striking the melting mass on its fiat surfaced bottom, the whole functioning for the purposes and in the manner, substantially as described.

2. A potless melting furnace, adapted to be disposed in substantial horizontal posi tion, having a melting chamber provided with a front outwardly projecting inclined wall, a fuel inlet toward the top rear end of said chamber, and an outlet through said front wall, the interior face of which latter serves as a reverberating surface, in combination with means for introducing a fuel mixture, directed through said inlet, in the form of a strong blast flame projected across the top of said chamber and down its opposite side wall, for permitting of itssubstantial complete combustion before striking the melting mass, and the whole functioning for the purposes and in the manner, substantially as described.

3. The combination with a main support, of a potless melting furnace tiltingly mounted thereon to swing from a substantially horizontal position, the said furnace'inoluding a melting chamber having a flat surfaced bottom wall and a projecting conical front reverberating wall; a fuel inlet opening entering said chamber tangentially of its rear top wall; an outlet through said conical front wall; a burner associated with said inlet opening and having a fuel feed inlet and an air intake; a blower; means for operating the latter; an air conduit pipe leading from said blower to the air intake of said burner; and means for tilt-ing said furnace,

4 wall;

being hollow, the said furnaceincluding a melting chamber having a transversely arched top wall, a flat surfaced bottom Wall, and a projecting conical front reverberating a fuel inlet opening entering said chamber tangentiallyjof its rear arched top wall; a blower; means for operating the latter; an air conduit pipe leading from said blower to said hollow trunnion; a branch .0 air pipe leading from said hollow trunnion;

a fuel burner carried by said branch pipe,

and communicating therewith, in fixed a1ine ment with said inlet opening, the said burner having a fuel feed inlet; and means for-tilting said furnace, through its supports, the several elements and the whole arrangement functioning for the purposes and in the manner, substantially as described.

In testimon whereof, I afl'ix my signature.

T EODORE W. MUCKLE.

trunnioning 15 

